A J Paramyxovirus-vectored HIV vaccine induces humoral and cellular responses in mice.

Human immunodeficiency virus (HIV) infects and depletes CD4+ T-cells, resulting in Acquired Immunodeficiency Syndrome (AIDS) and death. Despite numerous clinical trials, there is no licensed HIV vaccine. The HIV envelope glycoprotein (env) is a major target for vaccine development, especially for the development of antibody-mediated protection. In this study, we used J paramyxovirus (JPV) as a viral vector to express HIV-env. We replaced the JPV small hydrophobic (SH) gene with HIV-env (rJPV-env). Intranasal rJPV-env immunization induced anti-HIV-gp120 IgG antibodies in mice. Furthermore, we examined the immunogenicity of homologous and heterologous prime/boost regimens with rJPV-env, parainfluenza virus 5 (rPIV5)-vectored HIV-env, and HIV-Gag-Env virus-like particles (VLPs). The rJPV-env/rPIV5-env heterologous prime/boost regimen induced the strongest humoral and cellular responses. Introducing a third dose of immunization, mice that received a viral-vectored prime had high levels of HIV-env-specific cellular responses, with group rJPV-env/rPIV5-env/VLP having the highest. Together, this work indicates that a heterologous combination of viral-vectored HIV-env vaccines and a HIV-Gag-Env VLP induces high levels of humoral and cellular responses against HIV in mice.

Evaluation of Cerebral Perfusion Pressure, Cerebral Blood Flow, and Cerebral Oxygenation at Different Head of Bed Positions Using Transcranial Doppler and Near-Infrared Spectroscopy in Postoperative Neurosurgical Patients.

OBJECTIVES: Nursing postoperative neurosurgical patients with head of bed (HOB) elevation beyond 30° might be desired at times to prevent pulmonary complications. Due to the paucity of studies determining the effect of HOB beyond 30° on cerebral perfusion pressure (CPP), cerebral blood flow (CBF), and regional cerebral oxygenation (rSO2), this study was designed. METHODS: A total of 40 patients following elective neurosurgery for supratentorial tumors were studied in the neurosurgical intensive care unit three hours following admission. They were assessed for CBF velocities of middle cerebral arteries on either side using transcranial color Doppler (TCCD), rSO2 using near-infrared spectroscopy (NIRS), and mean arterial pressure measured at tragus level at various HOB positions. The estimated cerebral perfusion pressure (CPPe) was calculated from TCCD parameters, and the estimated intracranial pressure (ICPe) was then derived. Their variations at different HOB positions were noted. RESULTS: TCCD parameters such as peak systolic velocity (PSV) and mean flow velocity (MFV) did not significantly vary upon elevating HOB from 0° to 30° but reduced significantly when HOB was further elevated to 60° (p < 0.05). ICPe reduced significantly with a change of HOB positions from 0° to 60° (p < 0.001), and a significant reduction in CPPe was noticed when HOB was elevated to 60° (67.2 ± 10.1 mmHg vs. 74.7 ± 11.2 mmHg at 0°). However, none of these HOB positions affected rSO2 values. CONCLUSION: Postoperative nursing with positions up to 60° HOB can be tried in indicated patients following elective neurosurgery when complemented with CBF velocity and rSO2 monitoring and in whom CPP-guided therapy is not preferred.

Epidemiology, clinical profile, and outcomes of CSF-diversion catheter-related infections - Prospective cohort study results from a single quaternary neurosurgery referral centre.

BACKGROUND: Device-associated CNS infections is a major subgroup of healthcare associated CNS infections. Healthcare-associated ventriculitis or meningitis differs considerably from community-acquired meningitis in its epidemiology, pathogenesis, clinical presentation and management. OBJECTIVES: This study aimed to identify the infection rates, the associated risk factors, and outcomes of these life-threatening infections. METHODS: This was a 2-year single center prospective cohort study. Patient's clinical data, laboratory parameters, treatment and their outcomes were collected using data collection tool, and device days were collected from the hospital information system (HIS). Patients were categorised using IDSA criteria as contamination or colonisation or infection. Cox regression model was used for multivariate analysis to estimate hazard risk. RESULTS: A total of 578 CSF diversion catheters were inserted in 472 patients. The average rate for EVD and LD infection were 11.12 and 11.86 per 1000 device days respectively. The average infection rates for VP and LP shunts were 6% and 5.2% per procedure, respectively. The commonest etiological agent causing CSF diversion catheter-related infection (CDRI) was Klebsiella pneumoniae (n = 14, 40%). The risk factors which were independently associated with increased infection risk by cox regression analysis were drain insertion ≥7 days [HR:11.73, p -0.03], posterior approach of EVD insertion (occipital) [HR:9.53, p - 0.01], pre-OP ASA score>3 [HR:8.28, p - 0.013] presence of EVD/LD leak [HR: 17.24, p < 0.0001], male gender [HR:2.05, p-0.05] and presence of associated peri-operative scalp infections [HR:3.531, p-0.005]. Shift to narrow spectrum surgical prophylactic antibiotic [Coefficient: -1.284, p-0.03] and reduction in CSF sampling frequency [Coefficient: -1.741, p-0.02] were found to be negatively associated with CDRI. CONCLUSIONS: The study demonstrated drain insertion ≥7 days, posterior approach of EVD insertion, presence of EVD/LD leak, male gender and presence of associated peri-operative scalp skin and soft tissue infections were associated with increased risk of infection.

Injectable liposome-containing click hydrogel microparticles for release of macromolecular cargos.

Hydrogel microparticles ranging from 0.1-100 µm, referred to as microgels, are attractive for biological applications afforded by their injectability and modularity, which allows facile delivery of mixed populations for tailored combinations of therapeutics. Significant efforts have been made to broaden methods for microgel production including via the materials and chemistries by which they are made. Via droplet-based-microfluidics we have established a method for producing click poly-(ethylene)-glycol (PEG)-based microgels with or without chemically crosslinked liposomes (lipo-microgels) through the Michael-type addition reaction between thiol and either vinyl-sulfone or maleimide groups. Unifom spherical microgels and lipo-microgels were generated with sizes of 74 ± 16 µm and 82 ± 25 µm, respectively, suggesting injectability that was further supported by rheological analyses. Super-resolution confocal microscopy was used to further verify the presence of liposomes within the lipo-microgels and determine their distribution. Atomic force microscopy (AFM) was conducted to compare the mechanical properties and network architecture of bulk hydrogels, microgels, and lipo-microgels. Further, encapsulation and release of model cargo (FITC-Dextran 5 kDa) and protein (equine myoglobin) showed sustained release for up to 3 weeks and retention of protein composition and secondary structure, indicating their ability to both protect and release cargos of interest.

Is intraoperative electrocorticography (ECoG) for long-term epilepsy-associated tumors (LEATs) more useful in children?-A Randomized Controlled Trial.

OBJECTIVES: The utility of intraoperative electrocorticography (ECoG)-guided resective surgery for pediatric long-term epilepsy-associated tumors (LEATs) with antiseizure medication (ASM) resistant epilepsy is not supported by robust evidence. As epilepsy networks and their ramifications are different in children from those in adults, the impact of intraoperative ECoG-based tailored resections in predicting prognosis and influencing outcomes may also differ. We evaluated this hypothesis by comparing the outcomes of resections with and without the use of ECoG in children and adults by a randomized study. METHODS: From June 2020 to January 2022, 42 patients (17 children and 25 adults) with LEATs and antiseizure medication (ASM)-resistant epilepsy were randomly assigned to one of the 2 groups (ECoG or no ECoG), prior to surgical resection. The 'no ECoG' arm underwent gross total lesion resection (GTR) without ECoG guidance and the ECoG arm underwent GTR with ECoG guidance and further additional tailored resections, as necessary. Factors evaluated were tumor location, size, lateralization, seizure duration, preoperative antiepileptic drug therapy, pre- and postresection ECoG patterns and tumor histology. Postoperative Engel score and adverse event rates were compared in the pediatric and adult groups of both arms. Eloquent cortex lesions and re-explorations were excluded to avoid confounders. RESULTS: Forty-two patients were included in the study of which 17 patients were in the pediatric cohort (age < 18 years) and 25 in the adult cohort. The mean age in the pediatric group was 11.11 years (SD 4.72) and in the adult group was 29.56 years (SD 9.29). The mean duration of epilepsy was 9.7 years (SD 4.8) in the pediatric group and 10.96 (SD 8.8) in the adult group. The ECoG arm of LEAT resections had 23 patients (9 children and 14 adults) and the non-ECoG arm had 19 patients (8 children and 11 adults). Three children and 3 adults from the ECoG group further underwent ECoG-guided tailored resections (average 1.33 additional tailored resections/per patient.).The histology of the tailored resection specimen was unremarkable in 3/6 (50%).Overall, the commonest histology in both groups was ganglioglioma and the temporal lobe, the commonest site of the lesion. 88.23% of pediatric cases (n = 15/17) had an excellent outcome (Engel Ia) following resection, compared to 84% of adult cases (n = 21/25) at a mean duration of follow-up of 25.76 months in children and 26.72 months in adults (p = 0.405).There was no significant difference in seizure outcomes between the ECoG and no ECoG groups both in children and adults, respectively (p > 0.05). Additional tailored resection did not offer any seizure outcome benefit when compared to the non-tailored resections. CONCLUSIONS: The use of intraoperative electrocorticography in LEATs did not contribute to postoperative seizure outcome benefit in children and adults. No additional advantage or utility was offered by ECoG in children when compared to its use in adults. ECoG-guided additional tailored resections did not offer any additional seizure outcome benefit both in children and adults.

Regulation of host gene expression by J paramyxovirus.

Paramyxoviruses are negative-sense, single-stranded RNA viruses that are associated with numerous diseases in humans and animals. J paramyxovirus (JPV) was first isolated from moribund mice (Mus musculus) with hemorrhagic lung lesions in Australia in 1972. In 2016, JPV was classified into the newly established genus Jeilongvirus. Novel jeilongviruses are being discovered worldwide in wildlife populations. However, the effects of jeilongvirus infection on host gene expression remains uncharacterized. To address this, cellular RNA from JPV-infected mouse fibroblasts was collected at 2, 4, 8, 12, 16, 24, and 48 hours post-infection (hpi) and were sequenced using single-end 75 base pairs (SE75) sequencing chemistry on an Illumina NextSeq platform. Differentially expressed genes (DEGs) between the virus-infected replicates and mock replicates at each timepoint were identified using the Tophat2-Cufflinks-Cuffdiff protocol. At 2 hpi, 11 DEGs were identified in JPV-infected cells, while 1,837 DEGs were detected at 48 hpi. A GO analysis determined that the genes at the earlier timepoints were involved in interferon responses, while there was a shift towards genes that are involved in antigen processing and presentation processes at the later timepoints. At 48 hpi, a KEGG analysis revealed that many of the DEGs detected were involved in pathways that are important for immune responses. qRT-PCR verified that Rtp4, Ifit3, Mx2, and Stat2 were all upregulated during JPV infection, while G0s2 was downregulated. After JPV infection, the expression of inflammatory and antiviral factors in mouse fibroblasts changes significantly. This study provides crucial insight into the different arms of host immunity that mediate Jeilongvirus infection. Understanding the pathogenic mechanisms of Jeilongvirus will lead to better strategies for the prevention and control of potential diseases that may arise from this group of viruses.

EUS-guided Gastroenterostomy: A Multicenter International Study Comparing Benign and Malignant Diseases.

BACKGROUND: Endoscopic ultrasound (EUS)-guided gastroenterostomy (EUS-GE) is a minimally invasive therapy for patients with gastric outlet obstruction without the risks of surgical bypass and the limited long-term efficacy of enteral self-expanding metal stent placement. However, due to its novelty, there is a lack of significant data comparing long-term outcomes of patients with EUS-GE, based on the underlying disease. In this study, we compare outcomes of EUS-GE on benign versus malignant indications. METHODS: Consecutive patients from 12 international, tertiary care centers who underwent EUS-GE over 3 years were extracted in a retrospective registry. Demographic characteristics, procedure-related information and follow-up data was collected. Primary outcome was the rate of adverse events associated with EUS-GE and the comparison of the rate of adverse events in benign versus malignant diseases. Secondary outcomes included technical and clinical success as well as hospitalization admission. RESULTS: A total of 103 patients were included: 72 malignant and 31 benign. The characteristics of the patients undergoing EUS-GE is shown in Table 1. The mean age of the cohort was 68 years and 58 years for malignant and benign etiology. Gender distribution was 57% and 39% being females in malignant and benign etiology group, respectively. Clinical success, technical success, average procedure time, and hospital length of stay were similar in both groups. Patients with benign underlying etiology had significantly higher number of surgically altered midgut anatomy (P=0.0379). CONCLUSION: EUS-GE is equally efficient regardless of the underlying etiology (malignant vs. benign), and the adverse events both groups were comparable.

Pterional Approach for Anterior Skull Base Midline Meningiomas against "The More The Merrier" Approach: An Institutional Experience.

Objective Anterior midline skull base meningiomas involving olfactory groove, planum sphenoidale, and tuberculum sellae were usually managed with bifrontal craniotomy until the dawn of advanced microsurgical techniques. With the emergence of microsurgical techniques, midline meningiomas could be tackled solely from a unilateral pterional approach. We present our experience with pterional approach in managing anterior skull base midline meningiomas, including the technical nuances and outcomes. Methods Fifty-nine patients who underwent excision of anterior skull base midline meningiomas through a unilateral pterional craniotomy between 2015 and 2021 were retrospectively analyzed. The surgical technique and patient outcomes in the context of visual, behavioral, olfaction, and quality of life were evaluated during the follow-up. Results A total of 59 consecutive patients were assessed over an average follow-up period of 26.6 months. Twenty-one (35.5%) patients had planum sphenoidale meningioma. Olfactory groove and tuberculum sellae meningioma groups consist of 19 (32%) patients each. Visual disturbance was the predominant symptom with almost 68% of patients presented with it. A total of 55 (93%) patients had complete excision of the tumor with 40 patients (68%) achieving Simpson grade II excision, and 11 (19%) patients had Simpson grade I excision. Among operated cases, 24 patients (40%) had postoperative edema among which 3 (5%) patients had irritability and 1 patient had diffuse edema requiring postoperative ventilation. Only 15 (24.6%) patients had contusion of the frontal lobe and were managed conservatively. Five patients (50%) with seizures had an association with contusion. Sixty-seven percent of patients had improvements in vision and 15% of patients had a stable vision. Only eight (13%) patients had postoperative focal deficits. Ten percent of patients had new-onset anosmia. The average Karnofsky score was improved. Only two patients had recurrence during follow-up. Conclusion A unilateral pterional craniotomy is a versatile approach for the excision of anterior midline skull base meningioma, even for the larger lesions. The ability of this approach in the visualization of posterior neurovascular structures at the earlier stages of surgery while avoiding the opposite frontal lobe retraction and frontal sinus opening makes this approach more preferable over the other approaches.

α-Hemolysin promotes uropathogenic E. coli persistence in bladder epithelial cells via abrogating bacteria-harboring lysosome acidification.

There is a growing consensus that a significant proportion of recurrent urinary tract infections are linked to the persistence of uropathogens within the urinary tract and their re-emergence upon the conclusion of antibiotic treatment. Studies in mice and human have revealed that uropathogenic Escherichia coli (UPEC) can persist in bladder epithelial cells (BECs) even after the apparent resolution of the infection. Here, we found that, following the entry of UPEC into RAB27b+ fusiform vesicles in BECs, some bacteria escaped into the cytoplasmic compartment via a mechanism involving hemolysin A (HlyA). However, these UPEC were immediately recaptured within LC3A/B+ autophagosomes that matured into LAMP1+ autolysosomes. Thereafter, HlyA+ UPEC-containing lysosomes failed to acidify, which is an essential step for bacterial elimination. This lack of acidification was related to the inability of bacteria-harboring compartments to recruit V-ATPase proton pumps, which was attributed to the defragmentation of cytosolic microtubules by HlyA. The persistence of UPEC within LAMP1+ compartments in BECs appears to be directly linked to HlyA. Thus, through intravesicular instillation of microtubule stabilizer, this host defense response can be co-opted to reduce intracellular bacterial burden following UTIs in the bladder potentially preventing recurrence.

The influence of tumor topography on the surgical outcome of craniopharyngiomas.

OBJECTIVE: Various topographical classifications for craniopharyngioma have been proposed based on their relationship with optic chiasm and the third ventricular floor. There is a paucity of literature evaluating the surgical outcome based on tumor topography. This study aims to compare the surgical outcomes of retrochiasmatic craniopharyngiomas (RCPs) and nonretrochiasmatic craniopharyngiomas (non-RCPs). METHODS: This retrospective study includes newly diagnosed patients with craniopharyngioma who underwent surgery between January 2000 and December 2015. Clinical features, the extent of resection (EOR), surgical outcomes, tumor recurrence, and progression-free survival (PFS) of craniopharyngiomas were compared with respect to their relationship to the optic chiasm and third ventricular floor. RESULTS: The authors identified RCPs in 104 and non-RCPs in 33 patients. RCPs were significantly larger and more associated with hydrocephalus than were non-RCPs (p < 0.001) at the time of diagnosis. Puget grade 2 hypothalamic involvement was more frequent with RCPs. EOR and PFS following either subtotal resection (p = 0.07) or gross-total resection (p = 0.7) were comparable between RCPs and non-RCPs. There was no significant difference in the postoperative visual outcome. Resection of RCPs resulted in higher postoperative hypopituitarism (64% vs 42%, p = 0.01) and hypothalamic dysfunction (18% vs 3%, p = 0.02). Location of the tumor, either retrochiasmatic (HR 0.5; 95% CI 0.14-2.2; p = 0.4) or nonretrochiasmatic (HR 1.3; 95% CI 0.3-5.5; p = 0.6), did not show association with recurrence. RCPs with extra- and intraventricular components (type 3b) had a higher incidence of postoperative hypothalamic morbidities (p = 0.01) and tumor recurrence (36% vs 19%; p = 0.05) during follow-up than the extraventricular (type 3a) RCP. Between prechiasmatic and infrachiasmatic/intrasellar craniopharyngiomas, EOR (p = 0.7), postoperative diabetes insipidus (p = 0.4), endocrinological outcome (p = 0.7), and recurrence (p = 0.1) were comparable. The patients with complex multicompartmental tumors had a lower rate of gross-total resection (25%, p = 0.02) and a higher incidence of tumor recurrence (75%, p = 0.004) than the rest. CONCLUSIONS: The tumor topography can influence the postoperative outcome. RCPs can be associated with a higher incidence of hypopituitarism and hypothalamic morbidities postoperatively. The influence of topography on EOR and tumor recurrence is controversial. However, this study did not find a significant difference in EOR and tumor recurrence between RCPs and non-RCPs. PFS and overall mortality are also comparable.

Oscillatory shear stress modulates Notch-mediated endothelial mesenchymal plasticity in cerebral arteriovenous malformations.

BACKGROUND: Cerebral arteriovenous malformations (cAVM) are a significant cause of intracranial hemorrhagic stroke and brain damage. The arteriovenous junctions in AVM nidus are known to have hemodynamic disturbances such as altered shear stress, which could lead to endothelial dysfunction. The molecular mechanisms coupling shear stress and endothelial dysfunction in cAVMs are poorly understood. We speculated that disturbed blood flow in artery-vein junctions activates Notch receptors and promotes endothelial mesenchymal plasticity during cAVM formation. METHODS: We investigated the expression profile of endothelial mesenchymal transition (EndMT) and cell adhesion markers, as well as activated Notch receptors, in 18 human cAVM samples and 15 control brain tissues, by quantitative real-time PCR (qRT-PCR) and immunohistochemical evaluation. Employing a combination of a microfluidic system, qRT-PCR, immunofluorescence, as well as invasion and inhibitor assays, the effects of various shear stress conditions on Notch-induced EndMT and invasive potential of human cerebral microvascular endothelial cells (hCMEC/d3) were analyzed. RESULTS: We found evidence for EndMT and enhanced expression of activated Notch intracellular domain (NICD3 and NICD4) in human AVM nidus samples. The expression of transmembrane adhesion receptor integrin α9/ß1 is significantly reduced in cAVM nidal vessels. Cell-cell adhesion proteins such as VE-cadherin and N-cadherin were differentially expressed in AVM nidus compared with control brain tissues. Using well-characterized hCMECs, we show that altered fluid shear stress steers Notch3 nuclear translocation and promotes SNAI1/2 expression and nuclear localization. Oscillatory flow downregulates integrin α9/ß1 and VE-cadherin expression, while N-cadherin expression and endothelial cell invasiveness are augmented. Gamma-secretase inhibitor RO4929097, and to a lesser level DAPT, prevent the mesenchymal transition and invasiveness of cerebral microvascular endothelial cells exposed to oscillatory fluid flow. CONCLUSIONS: Our study provides, for the first time, evidence for the role of oscillatory shear stress in mediating the EndMT process and dysregulated expression of cell adhesion molecules, especially multifunctional integrin α9/ß1 in human cAVM nidus. Concomitantly, our findings indicate the potential use of small-molecular inhibitors such as RO4929097 in the less-invasive therapeutic management of cAVMs.

Assessment of Midline Shift in Postdecompressive Craniectomy Patients in Neurocritical Care: Comparison between Transcranial Ultrasonography and Computerized Tomography.

Background: Monitoring and evaluation of intracranial structures remain a fundamental element in the neurointensive care unit. Most used technique to monitor progression is the use of computed tomography (CT) in intracranial hemorrhage (ICH) or stroke. Rapid assessment of brain pathology can be made using CT to analyze the midline shift (MLS), hematoma expansion, and ventricular size, but transferring a patient who is intubated is time and resource-consuming task. Ultrasonography is a noninvasive technique, portable, and has the possibility of fast interpretation. Aims and Objectives: To measure the brain MLS in decompressive craniectomy patients using transcranial ultrasonography (TCS) and compare the correlation of these results with CT scan measurements of MLS in the same patient. Materials and Methods: Patients who have undergone decompressive craniectomy due to various reasons like ICH, traumatic brain injury, etc., and have a MLS. Trans cranial ultrasonography was assessed by a single consultant (Neuro Critical Care Intensivist) who was blinded for the CT scan measurement. CT scan measurement of MLS was assessed by a neuroradiologist using standard guidelines, who was blinded for the TCS results of MLS. The finding of a MLS >0.5 cm in the CT scan was considered a significant MLS. Results: A total of 31 patients were recruited for the study. MLS measured using CT was 0.91 ± 0.67 cm. MLS via TCS was 0.91 ± 0.66 cm. A significant MLS via TCS was found in 77.4%. Intraclass correlation coefficient (ICC) was calculated between CT-MLS and TCS MLS and obtained the value of ICC as 0.996, indicating an almost perfect agreement. Conclusion: Patients after decompressive craniectomy may present as an ideal candidate to visualize intracerebral anatomy with a high resolution. TCS might be considered as an alternative to CT to measure MLS in decompressive craniectomy patients.

Analysis of Prognostic Factors, Extent of Resection, and Long-Term Outcome of Craniopharyngioma in Adults and Children.

Introduction: Surgical management of craniopharyngioma is debatable and still lacks clear guidelines. Long-term complications are attributed to radical resection of the tumor. Extent of resection may not be the only factor which determines the functional outcome, because studies have reported hypothalamic and visual morbidities even with conservative resection. In this article, we analyze the extent of resection, long-term outcome, and various prognostic factors in adults and children. Materials and Methods: Newly diagnosed cases of craniopharyngioma operated between 2001 and 2013 were reviewed retrospectively. PFS and OS were calculated. Predictors of various outcome parameters were analyzed. Results: Of 140 patients, 41% were children and 59% were adults. Postoperatively, vision has improved in 63% and worsened in 12%. GTR was achieved in 66%. The median follow-up was 67 months. PFS at 5 and 10 years was 95% and 41.5%, respectively. OS at 5 and 10 years was 92.6% and 89.5%, respectively. Symptoms of raised ICP and hypothalamic involvement, extensive calcifications, tumor size >5 cm, and multi-compartmental tumors were associated with presence of residual tumor. Regression analysis showed symptoms of hypothalamic involvement, size of the tumor > 5 cm, and hydrocephalus predicted postoperative hypothalamic morbidities. No significant difference was found in postoperative visual, endocrinological, hypothalamic, and functional outcomes between GTR and STR. Conclusion: Conservative resection should be carried out in patients with preoperative hypothalamic symptoms and imaging evidence of extensive hypothalamic involvement. Size of the tumor and invasiveness are the other factors should be considered before radical excision of craniopharyngiomas.

DNA methylation signatures on vascular differentiation genes are aberrant in vessels of human cerebral arteriovenous malformation nidus.

Arteriovenous malformation (AVM) is a tangle of arteries and veins, rupture of which can result in catastrophic hemorrhage in vulnerable sites such as the brain. Cerebral AVM is associated with a high mortality rate in humans. The causative factor or the stimulus at the artery-venous junction and the molecular basis of the development and progression of cerebral AVM remain unknown. While it is known that aberrant hemodynamic forces in the artery-vein junction contribute to the development of AVMs, the mechanistic pathways are unclear. Given that various environmental stimuli modulate epigenetic modifications on the chromatin of cells, we speculated that misregulated DNA methylome could lead to cerebral AVM development. To identify the aberrant epigenetic signatures, we used AVM nidus tissues and analyzed the global DNA methylome using the Infinium DNA methylome array. We observed significant alterations of DNA methylation in the genes associated with the vascular developmental pathway. Further, we validated the DNA hypermethylation by DNA bisulfite sequencing analysis of selected genes from human cerebral AVM nidus. Taken together, we provide the first experimental evidence for aberrant epigenetic signatures on the genes of vascular development pathway, in human cerebral AVM nidus.

Mast cell regranulation requires a metabolic switch involving mTORC1 and a glucose-6-phosphate transporter.

Mast cells (MCs) are granulated cells implicated in inflammatory disorders because of their capacity to degranulate, releasing prestored proinflammatory mediators. As MCs have the unique capacity to reform granules following degranulation in vitro, their potential to regranulate in vivo is linked to their pathogenesis. It is not known what factors regulate regranulation, let alone if regranulation occurs in vivo. We report that mice can undergo multiple bouts of MC regranulation following successive anaphylactic reactions. mTORC1, a nutrient sensor that activates protein and lipid synthesis, is necessary for regranulation. mTORC1 activity is regulated by a glucose-6-phosphate transporter, Slc37a2, which increases intracellular glucose-6-phosphate and ATP during regranulation, two upstream signals of mTOR. Additionally, Slc37a2 concentrates extracellular metabolites within endosomes, which are trafficked into nascent granules. Thus, the metabolic switch associated with MC regranulation is mediated by the interactions of a cellular metabolic sensor and a transporter of extracellular metabolites into MC granules.

Lactobacillus crispatus Limits Bladder Uropathogenic E. coli Infection by Triggering a Host Type I Interferon Response.

Many urinary tract infections (UTIs) are recurrent because uropathogens persist within the bladder epithelial cells (BECs) for extended periods between bouts of infection. Because persistent uropathogens are intracellular, they are often refractive to antibiotic treatment. The recent discovery of endogenous Lactobacillus spp. in the bladders of healthy humans raised the question of whether these endogenous bacteria directly or indirectly impact intracellular bacterial burden in the bladder. Here, we report that in contrast to healthy women, female patients experiencing recurrent UTIs have a bladder population of Lactobacilli that is markedly reduced. Exposing infected human BECs to L. crispatus in vitro markedly reduced the intracellular uropathogenic Escherichia coli (UPEC) load. The adherence of Lactobacilli to BECs was found to result in increased type I interferon (IFN) production, which in turn enhanced the expression of cathepsin D within lysosomes harboring UPECs. This lysosomal cathepsin D-mediated UPEC killing was diminished in germ-free mice and type I IFN receptor-deficient mice. Secreted metabolites of L. crispatus seemed to be responsible for the increased expression of type I IFN in human BECs. Intravesicular administration of Lactobacilli into UPEC-infected murine bladders markedly reduced their intracellular bacterial load suggesting that components of the endogenous microflora can have therapeutic effects against UTIs.